file_name_c = 'cat.txt'
file_name_d = 'dogs.txt'
file_names = [file_name_c, file_name_d]
for file_name in file_names:
    try:
        with open(file_name) as file_obj:
            msg = file_obj.read()
            print(file_name + ':')
            print(msg)
    except FileNotFoundError:
        print('The file ' + file_name + ' do not exist.')